Little information is currently available concerning the neuroendocrine regulation of reproduction in the insect order Lepidoptera. This is unfortunate, since this order is large, biologically important, and a group containing many insect pest species of considerable economic and agricultural importance. Detailed studies of the regulation of reproduction in this order could therefore prove to be extremely valuable to reproductive biologists generally and, more specifically, to those interested in the regulation of lepidopteran, and other insect, populations. We therefore propose an intensive comparative examination of the reproductive biology of two distantly related lepidopteran species, each of which has apparently evolved fundamentally different mechanisms to solve the problems of successful reproduction. The specific objects of this research will be to obtain: 1) data concerning the structural alterations occurring in the neuroendocrine systems during periods of reproductive activity and inactivity; 2) data elucidating hormone action and interaction in the control of reproduction; 3) data identifying the external environmental factors regulating reporduction, and clarifying the method by which such factors interact with the neuroendocrine systems; and 4) data dealing with the neuroendocrine regulation of reproductively significant protein, lipid, and carbohydrate metabolism. For this research we will use classical morphological techniques, traditional endocrine methodology, programmed environmental chambers, quantitative biochemical analyses, electrophoresis, and eventually, immunochemical techniques.